1. Field of the Invention
The present invention relates to an image matching system for matching images based on image information of for example fingerprint images, still images, and moving images and an image matching method and program.
2. Description of the Related Art
Conventionally, as a method for matching images based on image information, various pattern matching techniques have been known. For example, the technique of detecting an amount of parallel movement and a rotation angle between a registered image and a matching image to be compared with and positioning the two based on the detection results has been proposed. Further, a pattern matching technique for performing a discrete Fourier transform for each of the registered image and the matching image, calculating a degree of correlation based on phase information of each of the obtained pattern data, and matching the images based on the correlation result has been known (for example, see Japanese Unexamined Patent Publication (Kokai) No: 10-55439).
Summarizing the problem to be solved by the invention, the above pattern matching system detecting the amount of parallel movement and the rotation angle, however, cannot obtain correspondence of images and suitably match images when for example the scalings of the registered image and the matching image are different. Further, the pattern matching system performing the discrete Fourier transform and matching images based on the amplitude component of each of the obtained pattern data processes the registered image or the matching image to scale it based on the amplitude component and matches the images based on the processing results, but cannot detect the rotation angle. For this reason, an image matching system for matching two images even if there are differences in the amount of parallel movement, the rotation angle, and the scaling between images has been demanded.